Device for measuring the location, the attitude and/or the change in location or, respectively, attitude of a rigid body in space

Abstract

In the illustrated embodiment, a field generator may be arranged on the body or at an interval therefrom, and produces a defined irregular field. For detecting the field flux a first surface with a plurality of sensor elements is provided, at least a part of which is distributed in two lines running parallel to each other and coupled electrically differentially together. At an interval from the first surface there is provided a second surface, parallel thereto, with further, correspondingly arranged sensor lines. The sensor lines of both surfaces run parallel to one another; the differential signals of the line pair of the first surface are electrically differentially linked to the differential signals of the line pair of the second surface. The device is in particular intended for measuring the location, the attitude and/or the change in location or, respectively, attitude of the jaw or of a tooth of a patient. Thus information may be provided with respect to three degrees of freedom of both translational and rotational movement.

I claim as my invention: 
     
       1. A system for measuring and registering information with respect to location and attitude of a rigid body in space, said system comprising a field generator arranged in fixed relation to the body, flux responsive means for mounting independently of the field generator and at an interval therefrom, and for supplying electrical signals in accordance with field flux from the field generator to represent positional information with respect to the body, and an electronic unit coupled with said flux reponsive means for obtaining and evaluating the electrical signals from the flux responsive means, characterized in said field generator being constructed such that it produces a defined irregular field, and said flux responsive means comprising at least one first surface, said first surface having a plurality of sensor elements, at least a part of which are arranged to form first sensor lines running parallel to each other, the sensor elements of the respective first sensor lines providing respective outputs and such respective outputs being electrically differentially coupled together for supplying a first differential signal, and comprising at least one second surface disposed between the field generator and the first surface, and parallel to the first surface to form a pair therewith and at an interval therefrom, the second surface having a plurality of second sensor lines comprising series of sensor elements extending parallel to respective sensor lines of the first surface, with the sensor elements of the respective second sensor lines of the second surface providing respective outputs and such outputs being electrically differentially coupled together for supplying a second differential signal, and said electronic device having means for differentially combining the first and second differential signals with respect to the first and second surfaces of said pair, said field generator comprising means for producing a magnetic field of irregular field configuration such that the output from said last mentioned means is responsive to relative rotation of said field generator while being relatively insensitive to translational components of movement of the field generator over a range of movement to be measured. 
     
     
       2. A system according to claim 1, characterized in one of said first and second surface additionally having a sensor array comprising a plurality of further sensor elements for supplying further signals in accordance with field flux from the field generator, the electronic device having means for additively combining said further signals with respect to said sensor array. 
     
     
       3. A system according to claim 2, characterized in the further sensor elements being arranged between respective sensor lines of said one surface. 
     
     
       4. A system according to claim 1, 2 or 3, characterized in said pair of said first and second surface (e.g. 7a, 7b) comprising a respective pair of first and second plane carrier sections (16, 20) situated opposite and parallel to each other at an interval (d) and mounting the respective first and second sensor lines (A, B; C, D) in such a way that respective ones of the first and second sensor lines (A, C; B, D) of each of the respective pairs of carrier sections (16, 20) are arranged parallel to one another. 
     
     
       5. A system according to claim 1, 2 or 3, characterized in said flux responsive means comprising three pairs of said first and second surfaces (7a, 7b; 8a, 8b; 9a, 9b) arranged in planes perpendicular to one another. 
     
     
       6. A system for measuring and registering information with respect to location and attitude of a rigid body in space, said system comprising a field generator arranged in fixed relation to the body, flux responsive means for mounting independently of the field generator and at an interval therefrom, and for supplying electrical signals in accordance with field flux from the field generator to represent positional information with respect to the body, and an electronic unit coupled with said flux responsive means for obtaining and evaluating the electrical signals from the flux responsive means, characterized in said field generator (3) being constructed such that it produces a defined irregular field, and said flux responsive means comprising at least one first surface, said first surface having a plurality of sensor elements (17, 18, 19), at least a part of which (18, 19) are arranged to form first sensor lines (A, B) running parallel to each other, the sensor elements of the respective first sensor lines being electrically differentially coupled together for supplying a first differential signal, and comprising at least one second surface disposed parallel to the first surface to form a pair therewith and at an interval therefrom, the second surface having a plurality of second sensor lines (C, D) comprising series of sensor elements (21, 22) extending parallel to respective sensor lines (A, B) of the first surface, with the sensor elements of the respective second sensor lines (C, D) of the second surface being electrically differentially coupled together for supplying a second differential signal, and said electronic device having means for differentially combining the first and second differential signals with respect to the first and second surfaces of said pair, said first surface (e.g. 7b) additionally having a sensor array (E) comprising a plurality of further sensor elements (17) for supplying further signals in accordance with field flux from the field generator (3), the electronic device having means for additively combining said further signals with respect to said sensor array (E), the flux responsive means comprising three pairs of said first and second surfaces, each pair of said first and second surfaces comprising first and second carrier sections (16, 20) having mounted thereon the first and second sensor lines (A, B; C, D) and the further sensor arry (E), the respective pairs of said first and second carrier sections (16, 20) being parallel to respective planes which are perpendicular to one another. 
     
     
       7. A system for measuring and registering information with respect to location and attitude of a rigid body in space, said system comprising a field generator arranged in fixed relation to the body, flux responsive means for mounting independently of the field generator and at an interval therefrom, and for supplying electrical signals in accordance with field flux from the field generator to represent positional information with respect to the body, and an electronic unit coupled with said flux responsive means for obtaining and evaluating the electrical signals from the flux responsive means, characterized in said field generator (3) being constructed such that it produces a defined irregular field, and said flux responsive means comprising at least one first surface, said first surface having a plurality of sensor elements (17, 18, 19), at least a part of which (18, 19) are arranged to form first sensor lines (A, B) running parallel to each other, the sensor elements of the respective first sensor lines being electrically differentially coupled together for supplying a first differential signal, and comprising at least one second surface disposed parallel to the first surface to form a pair therewith and at an interval therefrom, the second surface having a plurality of second sensor lines (C, D) comprising series of sensor elements (21, 22) extending parallel to respective sensor lines (A, B) of the first surface, with the sensor elements of the respective second sensor lines (C, D) of the second surface being electrically differentially coupled together for suppling a second differential signal, and said electronic device having means for differentially combining the first and second differential signals with respect to the first and second surfaces of said pair, characterized in that, for compensating the earth's magnetic field, said system further comprises compensating arrays (12, 13, 14) of sensor elements rigidly connected in planes parallel to one another and parallel to the planes of the respective pairs (7, 8, 9) of said first and second surfaces. 
     
     
       8. A system according to claim 7, characterized in said system further comprising mounting means (6, 15) carrying three pairs (7, 8, 9) of said first and second surfaces arranged perpendicularly to each other, and having three compensating arrays (12, 13, 14) rigidly connected therewith, with each compensating array being parallel to one of said pairs (7, 8, 9) of said first and second surfaces. 
     
     
       9. A system for measuring and registering information with respect to location and attitude of a rigid body in space, said system comprising a field generator arranged in fixed relation to the body, flux responsive means for mounting independently of the field generator and at an interval therefrom, and for supplying electrical signals in accordance with field flux from the field generator to represent positional information with respect to the body, and an electronic unit coupled with said flux responsive means for obtaining and evaluating the electrical signals from the flux responsive means, characterized in said field generator (3) being constructed such that it produces a defined irregular field, and said flux responsive means comprising at least one first surface, said first surface having a plurality of sensor elements (17, 18, 19), at least a part of which (18, 19) are arranged to form first sensor lines (A, B) running parallel to each other, the sensor elements of the respective first sensor lines being electrically differentially coupled together for supplying a first differential signal, and comprising at least one second surface disposed parallel to the first surface to form a pair therewith and at an interval therefrom, the second surface having a plurality of second sensor lines (C, D) comprising series of sensor elements (21, 22) extending parallel to respective sensor lines (A, B) of the first surface, with the sensor elements of the respective second sensor lines (C, D) of the second surface being electrically differentially coupled together for supplying a second differential signal, and said electronic device having means for differentially combining the first and second differential signals with respect to the first and second surfaces of said pair, characterized in each of the sensor elements (17 to 22) having a structure of low-remanence magnetic material arranged in superimposed relation thereto. 
     
     
       10. A system for measuring and registering information with respect to location and attitude of a rigid body in space, said system comprising a field generator arranged in fixed relation to the body, flux responsive means for mounting independently of the field generator and at an interval therefrom, and for supplying electrical signals in accordance with field flux from the field generator to represent positional information with respect to the body, and an electronic unit coupled with said flux responsive means for obtaining and evaluating the electrical signals from the flux responsive means, characterized in said field generator (3) being constructed such that it produces a defined irregular field, and said flux responsive means comprising at least one first surface, said first surface having a plurality of sensor elements (17, 18, 19), at least a part of which (18, 19) are arranged to form first sensor lines (A, B) running parallel to each other, the sensor elements of the respective first sensor lines being electrically differentially coupled together for supplying a first differential signal, and comprising at least one second surface disposed parallel to the first surface to form a pair therewith and at an interval therefrom, the second surface having a plurality of second sensor lines (C, D) comprising series of sensor elements (21, 22) extending parallel to respective sensor lines (A, B) of the first surface, with the sensor elements of the respective second sensor lines (C, D) of the second surface being electrically differentially coupled together for supplying a second differential signal, and said electronic device having means for differentially combining the first and second differential signals with respect to the first and second surfaces of said pair, characterized in that Hall-effect magnetic field sensors are provided as the sensor elements (17 to 22). 
     
     
       11. A system for measuring and registering information with respect to location and attitude of a rigid body in space, said system comprising a field generator arranged in fixed relation to the body, flux responsive means for mounting independently of the field generator and at an interval therefrom, and for supplying electrical signals in accordance with field flux from the field generator to represent positional information with respect to the body, and an electronic unit coupled with said flux responsive means for obtaining and evaluating the electrical signals from the flux responsive means, characterized in said field generator (3) being constructed such that it produces a defined irregular field, and said flux responsive means comprising at least one first surface, said first surface having a plurality of sensor elements (17, 18, 19), at least a part of which (18, 19) are arranged to form first sensor lines (A, B) running parallel to each other, the sensor elements of the respective first sensor lines being electrically differentially coupled together for supplying a first differential signal, and comprising at least one second surface disposed parallel to the first surface to form a pair therewith and at an interval therefrom, the second surface having a plurality of second sensor lines (C, D) comprising series of sensor elements (21, 22) extending parallel to respective sensor lines (A, B) of the first surface, with the sensor elements of the respective second sensor lines (C, D) of the second surface being electrically differentially coupled together for supplying a second differential signal, and said electronic device having means for differentially combining the first and second differential signals with respect to the first and second surfaces of said pair, characterized in said field generator (3) comprising two magnetic field generator elements (3a, 3b) of similar configuration and each having a first pole of one magnetic polarity and a second pole of the opposite magnetic polarity, and having respective polar axes forming an included angle (α) of less than 180° and having the respective first poles of said one magnetic polarity arranged in confronting adjacent relation. 
     
     
       12. A system according to claim 11, characterized in that said two magnetic field generator elements comprise respective bar magnets (3a, 3b). 
     
     
       13. A system for measuring and registering information with respect to location and attitude of a rigid body in space, said system comprising a field generator arranged in fixed relation to the body, flux responsive means for mounting independently of the field generator and at an interval therefrom, and for supplying electrical signals in accordance with field flux from the field generator to represent positional information with respect to the body, and an electronic unit coupled with said flux respective means for obtaining and evaluating the electrical signals from the flux responsive means, characterized in said field generator (3) being constructed such that it produces a defined irregular field, and said flux responsive means comprising at least one first surface, said first surface having a plurality of sensor elements (17, 18, 19), at least a part of which (18, 19) are arranged to form first sensor lines (A, B) running parallel to each other, the sensor elements of the respective first sensor lines being electrically differentially coupled together for supplying a first differential signal, and comprising at least one second surface disposed parallel to the first surface to form a pair therewith and at an interval therefrom, the second surface having a plurality of second sensor lines (C, D) comprising series of sensor elements (21, 22) extending parallel to respective sensor lines (A, B) of the first surface, with the sensor elements of the respective second sensor lines (C, D) of the second surface being electrically differentially coupled together for supplying a second differential signal, and said electronic device having means for differentially combining the first and second differential signals with respect to the first and second surfaces of said pair, characterized in said system comprising mounting means applicable to the field of dentistry for mounting said flux responsive means, the field generator (3) being adapted to be fixed relative to the lower jaw of the patient. 
     
     
       14. A system according to claim 7 characterized in the system being adapted to be used in the field of dentistry and comprising mounting means for mounting said flux responsive means and comprising a bracket (15) which can be fixed on the head of a patient, said compensating sensor arrays (12, 13, 14) being attached to said bracket (15). 
     
     
       15. A system according to claim 11, characterized in that said system further comprises mounting means (6, 15) carrying three pairs (7, 8, 9) of said first and second surfaces arranged perpendicularly to each other with the three planes defined by the three pairs (7, 8, 9) of said first and second surfaces having a common point of intersection, said mounting means (6, 15) being constructed for fastening on the head of a patient, the field generator being arranged intraorally, and the two magnetic field generator elements, (3a, 3b) thereof having the angle bisector of their included angle (α) extending in the direction of the point of intersection of the three planes. 
     
     
       16. A system for measuring and registering information with respect to location and attitude of a rigid body in space, said system comprising a field generator arranged in fixed relation to the body, flux responsive means for mounting independently of the field generator and at an interval therefrom, and for supplying electrical signals in accordance with field flux from the field generator to represent positional information with respect to the body, and an electronic unit coupled with said flux responsive means for obtaining and evaluating the electrical signals from the flux responsive means, said field generator being constructed such that it produces a defined irregular field, and said flux responsive means comprising at least one first surface, said first surface having a plurality of sensor elements at least a part of which are arranged to form first sensor lines running parallel to each other, the sensor elements of the respective first sensor lines providing respective individual outputs and such respective individual outputs being electrically differentially coupled together for supplying a first differential signal, and comprising at least one second surface disposed between the field generator and the first surface, and parallel to the first surface to form a pair therewith and at an interval therefrom, the second surface having a plurality of second sensor lines comprising series of sensor elements extending parallel to respective sensor lines of the first surface, with the sensor elements of the respective second sensor lines of the second surface providing respective individual outputs and such respective individual outputs being electrically differentially coupled together for supplying a second differential signal, and said electronic device having combining means for differentially combining the first and second differential signals with respect to the first and second surfaces of said pair. 
     
     
       17. A system according to claim 16 with said flux responsive means comprising three pairs of said first and second surfaces (7a, 7b; 8a, 8b; 9a, 9b) arranged in planes perpendicular to one another. 
     
     
       18. A system according to claim 1, with said pair of said first and second surface (e.g. 7a, 7b) comprising a respective pair of first and second plane carrier sections (16, 20) situated opposite and parallel to each other at an interval (d) and mounting the respective first and second sensor lines (A, B; C, D) in such a way that respective ones of the first and second sensor lines (A, C; B, D) of each of the respective pairs of carrier sections (16, 20) are arranged parallel to one another, said flux responsive means comprising three pairs of said first and second surfaces (7a, 7b; 8a, 8b; 9a, 9b) arranged in planes perpendicular to one another.